Drop hammer



June 30, 1931. F c IN 1,812,464

DROP LHAMMER Filed Aug. 1925 2 Sheets-Sheet 1 Sylvan-(o1 June 30, 1931. B N 1,812,464

DROP HAMMER Patented June 30, 1931 amiss erases PATENT OFFIGE enemas, on mem s, "CONNECTICUT, A-ssI'GNon in THE :mLLmGs a "Gotten-NY, or ammonia, CONNECTICUT, A CORPORATION 01* common- CUT DROP HAMMER a e-imam filed August '30, 1923. Serial-No. 680,129.

. This invention relates to drop hammers of the type having a hammer suitably guided for vertical movement, a board connected thereto, lifting rolls adapted to -grip the board to. raise-the same and the hammer, and a friction 'har associated with the rolls and adapted to control the gripping engagement t'hereofon the board. The invention has as its aim to provide, in a machine of this sort, various features of advantage. N

One aim of the invention is to provide an improved friction bar and an improved arrangement of parts for connecting the same Witlith-e lifting roll, or rolls, the bar and the connection therefor being of economical and "strong construction, each of the parts heir. g

' r'e'lative'ly'simple in design so that they can b'e cheap-1y manufactured. The arrangement is such that'the danger of the bar breaking is reduced to a minimum, but, in the event that it :shou-ld break. under the strains and stresses 'to'which it is subjected, it may be readily replaced 'at a low cost.

Anotherob-jeot of the invention is to provide an improved cushioning or'yielding 'co'nnectionhetween the hammer and the board so-that the strains to which the board is suhj'ct ed are reduced to aminimum.

Ot-he'r' fdhject's of the invention will be in obvious and in part pointed out herein'after. y

- The invention accordingly consists in the featiu i es of construction,"combination of 'elements andfar'rangementof parts which will be exemplified in the con'struc tion hereinafter set forth, andthe scope of the application of which will be indicated in the appended claims. 7

I In the drawings forming a part of this snecifica't'i'on and in Whichisimi'lar reference characters refer to similar parts:

Figure-1 is a front view of a drop hammer in which my improvements are incor jorated; 2 is a detail view of the roll operating mechanism; 1

3-is across section of a hammer and its connection vtoithe board, showing one form .ofshock absorbing means; 7

. y F 1g. 4 is anew snnllar to Fig. 3, but showing a modified form of shock absorbing mechanism. v r

, Fig. 5 is a plan of the essential parts or the head strncture, and

Fig. 6 a detailof the friction har rock link.

Referring tothe drawings and, more particularly, to Figs. .1 and 2, the machine is shown as having a frame including a pair of uprights 10 and 11 which are formed so as to provide Ways for a hamme-rlQ to be suitably guided in its rise and fall. Supported by the uprights 10 and 1,1 is ahead 9,in Which is mounted the hammer lifting mechanism here shown, for illustrative purposes, as includingu pperand lower pairs or sets 13 and 14 of lifting rolls. The front rolls of eachp'air are fast on the shafts ammo, respectively. pairof belt driven pulleys l5 and 16, equally driven from an adjacent shaft, not shown, ate

attached tothe shafts oftthe rear rolls, and

the front rolls are driven from the spur gears 17 and 18 on said shafts meshing With gears 17 and 18 on the front shafts 25 andfae, allof the gears being-of equal size so as to drive the rolls at equal speeds. The front rolls are arranged to be slightly moved, laterally, into and out of engagement with the hoard 19 which is attached at its lower endto the hammer 12. This lateral movement accomplished (within thelength'of the inter-mesh of the spur.'gears) through the nieans'of "eccentric bearings 22 and23 in which the shafts 25 and 26 of the two front roll s. 13 and '14,, respectively, are jonrnalled The eccentric hearings are suitably journalled in the head 9. The pair of eccentrics 22, in which the opposite ends of the shaft 25 "a re liourna'lled, are connected h'yn'ieans of'a yoke 28. Like- Wisefthere is a yoke 29 which connects the eccentrics 23 in which the opposite ends of the shaft ,Q-Gare journalled. It will be seen that when the eccentrics 22 and "23 are rotated in a clockwise direction :2), the rolls are Withdrawn from the 'bfo'a'rd so that the hammer is free to drop, and,

upon rotation of the eccentrics "in the oprolls 13 and 14 be operated substantially in unison and, therefore, the yokes 28 and 29 are associated together by a connection including one or more links 31 two being shown in the present instance) and links and 36. Each of the links 31 is pivotally connected at its upper endto the upper eccentricyoke 23 by a pivot member or pin 44 and is provided at its lower end with an elongated hole 32 receiving a'pin 33 carried by the yoke 29. The pair of links 35 and 36 are connected together at their adjacent ends by a hearing or bolt 37, and these links are pivotally connected at their extreme ends to the respective eccentric yokes 28 and 29 by the pins 44 and 33, respectively. Connected to the bearing 37 and between the links 35 and 36 is a link bar'38, the lower end of which is guided by a rock link'40 pivoted to the frame as,-for instance,

at 41. The lower end of the link bar is pivotally connected to the free or outer end of the rock link by} a shaft 39.. The friction bar 42 issus'pended from the shaft 39 and is guided at its lower end in a suitable boss 43 on the upright 11, The rock link has. three spaced arms orhubs 40a, 40b and 4l)0. The lower end of the link bar 38 is positioned between the hubs 40-46 and 400, and the upper end of the friction bar is positioned between the hubs 40.a and 40b, the space between theselatter hubs being in substantially the'same vertical plane as the boss 43 so that the friction bar in front elevation is substantially straight. As shown most clearly in Fig. 1, thelinks 35 and 36 are bent in opposite directions so'that they straddle the upper end of the link bar 38, thus! avoiding any ,eccentric distribution of the forces applied on the yokes 28 and 29.

From the foregoing description, it will be "seen that the frictionbar. is devoid of any lateral twists or turns, which means that this barmay be very easily made and, also, that it is better enabled to withstand the strains and shocks towhich it is subjected when the machine is'in operation. Heretofore, it has 7 I been customary to make the friction bars with difficult bends, that is, the bars were turned f-inftowards the frame" and also offset towards the center of the machine, andwhen such bar's had to be replaced this could only be done at considerable expense and usually I after costly, delay. A frictionbar constructed in accordance with the present invention may ,be very easily replaced at a relatively low cost.f r o. The operation of the drop hammer will be readily understood;[Assuming that the hammer s in raised pos tion,- when 1t 18 desired to cause the hammer to drop, the opera- Jtor will releasecertain clamps (not shown) whereupon the hammer Wlll fall. I hammer approaches the end of 1ts downward.

strcl-re. the'cam surface 54 on the hammer will push ina plunger 53 and thereby withdraw the latch 51 against the tension of a spring,

As the not shown, from a shoulder 52 on the friction bar so that the friction bar will fall. WVhen the friction bar falls, it will exert, through the rock link 40 and the link bar 38,

a downward pull on the links 35 and 36, causthe rolls 13 and 14 can accommodate themselves to the board. When the hammer 'ap proaches the end of its upward stroke, it engages the free end of; a lever 46 adjustably pivoted to the frame or upright 11 and pivotally connected intermediate its ends to the friction bar 42. WVhen this lever is raised, it moves the friction bar upwardly causing the eccentrics to be rotated in a clockwise direction, which results in the rolls being with drawn from the board. The friction bar is held in its raised position by the latch 51 until the hammer again drops. I Z

It will be apparent that the rolls are pressed upon the board with equal force by virtue of the relation of the links and that by reason of the rock-link it is possible for the connection with the roll supports 22 and, 23 to be made centrally orintermediate of the roll journals, which is the position best suited for imparting equal pressure to both=journals off each roll, while at the same timecthe source of board-gripping pressure can be located at one side of the roll space, upon or in the plane of one of the frame uprights without subjecting any member to undue strain. Theinterven tion of the rock-link-between a friction bar and the equalizing linkage 35and 36 relieves the latter of any possible restraint to its compensating action due to'the resistance to lateral displacement of the friction bar; the upper end of the link bar 38 being free to accommodate any position that may be taken by the pivot pin 37. Inthi's respectparticularly, the rock-link exercises important functions in any type of board drop hammer, having upper and lower rolls intended to be equally pressed, with a compensating action, against the board,as will now be evident, and

it is intended to claim such rock link broadly as constituting this invention, without limitation to the particular k1nd of linkage or the particular source of board-gripping pressure.

- It is one of the features of the rock-link,

ofthe hammer 12. guide for theshajft '56.

equalizing linkage is "not herein claimed, as the same constitutes the subject. matter of a copending application Serial No. 660,137, filed'Augus't 30, 1 923. c

In accordance with thepresent invention, animproved shock absorbing or cushioning means is provided between theha'm'mer and the board in order to reduceto a minimum the strains and jars to which the board is subjected when the hammeris dropped onto the lower die. One form which my improved shock absorbing means may take is illustrated in Fig. 3. The board is secured at its lower end in anysuitable manner, as by means of a clamp 55, to a rod or post 56 projecting into a cylinderb? bored in the body of the hammer. On the end of this red is attached a suitable piston 58 shaped to conform with the lower end of the cylinder '57. The cylinder 57 and the piston 58 form a dash-pot, there being provided suit-able grooves '62 in the wall of the cylinder to form passes or ports which permit the air to pass from one side of the piston to the other. About the rod 56 is a coil spring 63bearing at its lower end against the piston 58 and at its upper end against a block orblocks 64 dovetailed into the upper face These blocks also form a The operation of the shock absorbing mechanism is such that, asthe hammer 12 hits the lower die, the motionof the hammer is arrested with such suddenness as to cause the piston to travel downwardly very quickly, thereby blocking off the ports 62andtrapping, in the lower end of the cylinder, a 'suffic'ient quantity of air toproduce the desired cushioning effect on the board. When the hammer board is gripped by the rolls 13 and 1 1, the piston will move upwardly relative to'the hammer, causing compression of thesprfing 63, and whenthis spring has been compressed to the predetermined extcnt,the piston and hammer will rise in unison. Thus, the board will gradually take up the Weight of the hammer instead of being subjected to a sudden shock which would occur if the board were rigidly secured to the hammer. NVhen the piston is thus 'raised relative to the hammer, com munication is established by means of-the ports '62 between the space above and below the piston so'that there willbe suflicient air beneath the piston to absorb the shock when the hammer is againdropped. In order to supply the cylinder with air, there is provided an aperture 65 permitting the cylinder to have direct communication with the atmos- 'phere.

Another embodiment of the shock absorbing mechanism is shown in Fig. 4;. In this embodiment, the dash-pot action is practicallyeliminated, and the shock is mainly absorbed by springs arranged in a novel manner for this purpose. The hammer 12 is pro- I vide'd with a cylinder 57 of the same form as in the embodiment "shown in Fig. :3, and a rod 56 extends through the blocks 64 into the cylinder. The piston, in this case, is in the form of a sleeve 67 which encloses a spring 63 of the general character described in connection with the embodiment shown in Fig. 3 and generally acts for the same purpose. At the top of the piston 67 there is provided a circumferential flange 68 which forms an abutment for a spring 69 coiled about the cylinder 67 and adapted to be compressed between the bottom of the cylinder 57 and the flange of the piston. Th'us, whe1i the hammer 12 stops suddenly, as, for instance, when it hits the bottom die, the rod 56 will be forced downwardly into the cylinder, forcing the piston down and compressing the spring 69 which relieves the board 19 of the force of the impact. Upon the appli cation of a sudden force to the rod 56, in an upward direction, the spring 63 absorbs the shock in the same manner as the spring 63 shown in Fig. 8. v Y V Thus, by the above construction, are accomplished, among others, the objects hereinbe fore referred to. V I e As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all inatter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a board drop hammer the combination of a hammer, and hammer board, boardlifting rolls, movable supporting means therefor, a rock "link pivoted on the machine frame independently of any roll-supporting means, a friction bar having its lowe'r partguided on the machine frame adjacent the path of the hammer and connected at its upper end to said rock link, a connection between said roll-supporting means and said rock link and means connected with the hammer for automatically moving said bar to produce sustained hammer operation.

. 2. In a board drop hammer, the combination of ahammer and hammer board, uprights in which the hammer is guided and a roll space above the hammer, board-lifting rolls in said space, movable supporting means therefor, a rock-link pivoted on the machine frame and extended horizontally from a point nearthe center of the frame to a point near the line of one of said uprights, a friction bar having its lowerpart guided on that upright adjacent the path of 4 the hammer and connected at its upper end to one side of sa d rock link, and a connection between said rock link and sald rollsupporting means for moving the latter to ward the hammer board.

connected at its upper end to" the side of said rock-link, and a connection between said rock link'and said roll-supporting means for moving the latter toward the hammer board.

4. In a'drop hammer, a board, a hammer connected thereto, hammer lifting mechanism including a plurality of rolls spaced apart longitudinally of the board, means for moving said rolls into and out of gripping en- 'gagement with said board and including eccentrics in which said rolls are journalled, yokes connecting the eccentrics of each roll, a link bar operatively connected to both yokes and extending beiow the same, means for guiding the lower end of said linkbar,

and afriction bar having its upper end pivotally connected to the lower end of said link bar.

5. In adrop hammer, a board, a hammer attached thereto, a plurality of sets of rolls spaced apart longitudinally of said board and arranged to move laterally into and out of engagement with said board, eccentric bearings for said rolls, yokes'fixed to said hear- I ings, a triangular system of links connecting said yokes whereby said rolls are moved into and out of engagement with said board, a link bar suspended from said system, a pivot member on said link bar, and a friction bar suspended from saidmember and laterall spaced from said linkzbar. I

6. In a drop hammer, a board, a hammer, a

cylinder within said hammer, a rod connected to said board and providedwith'a sleeve within said cylinder, a spring between said sleeve and said hammer and arranged'to'becompressed in movement of one direction of said hammer and a second s rin about said rod and within said sleeve arranged to'be c'ompressed in opposite movement of said hammer. j

7. In a drop hammer, a hammer, a board, a

7 cylinder within said hammer, a rod attached to said board, a sleeve in said cylinder and connected at 1ts lower end to sa d rod, said SIGQVQbGlIlg 1n the form of a cylindrical shell vabout said rod, a spring about said sleeve and compressible between said sleeve and said hammer, a second spring within saidvsleeve,

{ranged to guide said rod and retain said secondspring within said cyllnder.

and a block secured to said hammer and ar- 8, In a drop hammer, a board, a hammer, a

cylinder within said hammer, a rod fastened to said board and extending into said cylinthe form of a hollow cylinder outwardly flanged at its upper end, a spring between the periphery of said sleeve and said cylinder and adapted to be compressed'between said flange and the bottom of said cylinder, and a second spring within said sleeveand about said rod and adapted'to be compressed between'the bottom of said sleeve and the top of said cylinder. f f

9. In a board drop hammer thecombination with the machine frame and the board, of-a reciprocating member for imparting pressure to the lifting rolls, a rock link pivoted on the machine frame for guiding the movement of said member, upper and lower lifting rolls independently movable toward the board, supporting means for said respective rolls, pressure-equalizing means connecting said supporting means to said rock link and pressure-imparting member, and means for automaticallyactuating said member to produce sustained hammer operation; 7

10. Inaboard drop hammer, the combination'with the machine frame and the hammer board and upper and lower lifting rollers adapted for equalized pressure upon the board, of supporting means for the ]0111I1211S of said rolls whereby they aremoved into lifting positions, operating connections for said means extending downwardly in front of the rolls and including a rock link pivotally mounted on the machine frame below the'roll space, and a frictionbar member connected with said rock link in a laterally offset position with respect to said rolls.

11. In a board drophammer the combination with the hammer board, of a lifting roll, a movable roll support in which the same is jou'rnalled at its opposite ends andby means of which it is moved toward and fromthe board, a linkbar connected to said roll support and occupying a position intermediate of the roll journals, a rock link pivoted on the machine frame at one end and connected to and guiding said link bar at its other end, and actuating means for said roll support connected with said rock link at a point laterally spaced thereon from the point of connection of said link bar therewith,

12. In a board drop hammer, having frame uprights, the combination with the hammer board of aflifting roll, a movable roll-support in which the same is journalled and by which it is moved towardand from the board,v a vertical link bar connected to said roll sup port between the lateral limits. of the roll space, a rock link connected to said link bar and extended laterally to one side of the roll space, said link being pivoted on'the frame of the laterally extended part of said ro'ck link and extending down alongside of andguided on the adjacent frame upright.

' FREDERIC 'C. 'BILLINGS.

the machine, and a friction bar connected to 

